This is typical of the part of Fallsburg I've been working in for the past year. Roads and driveways often sit directly on top of the bedrock stone.
The most common rock types in the area are bluestone and a reddish shale.
When side-by-side, the blue sandstone takes on a bright green.
The shale - it's violet, pink, maroon, brick, brown and orange.
Puddles after a storm are blood red. As they evaporate, a dark red clay silt remains.
Shale = silt stone. These puddles were the prime places to hunt for clay. It was a frustrating process - there just were too few puddles. Instead, I decided to try to refine mud collected at the base of red shale outcrops. Three 5-gallon buckets of mud traveled back to Philly with me.
This was the beginning. The next step: refining.
BACK IN THE STUDIO
To extract clay from the soil collected, first, sift the dirt through a sieve made of 1/4" hardware cloth. This will take out large rocks, sticks, etc. If it catches large dried clumps of dirt, break them up by crushing them or pouring water through the sieve. This will also help to remove any clay from the sticks and rocks, transferring it to the more refined material in the bucket below.
Mix water into the sifted material (at least a 50/50 mix) and stir it to suspend the clay particles. Use your hands to squeeze clumps of clay so the particles will blend with the liquid. Pour this slurry in small batches through a finer sieve into a clean bucket below. Early on, I just used kitchenware for this sieve - an oil-spatter screen. You'll have to mush clumps through the screening, then rinse through with more water. You'll be left with a fine clay mix in the bucket below. Small rocks etc. will be caught in the sieve. Clean out the sieve frequently, and be careful to not contaminate the mixture below with what you've just sifted out. I sifted the material one additional time through a very fine piece of screen material, leaving nothing but silt and water.
Let the bucket sit for a day. The silt will settle to the bottom of the bucket, and the water can be siphoned off the top. If you do this every day for about 4-5 days, you'll be left with a thickened slip, which can be poured onto a plaster bat to dry.
The plaster will draw water out of the material. This is my first sample. Once it was dry enough to hold together, after experimenting with it a bit, it seemed to have potential as a workable clay.
Making a larger batch, cracks appeared in the drying process - a sign that there wasn't enough elasticity to be a workable material.
Next step: Firing.
During this time, I began to think about what should be made with the stuff, and wondered if it was food safe. As I researched the chemical elements in Marcellus shale, I learned that it is a black shale. This material was not Marcellus.
Now I know how to make clay from Catskill Red Shale...not exactly what I thought I was doing, but I'll take it.
The next challenge was to find Marcellus shale.